MicroRNAs (miRNAs) are small noncoding RNAs that negatively regulate protein-coding genes. To identify miRNAs that have a tumor suppressive function in bladder cancer (BC), 156 miRNAs were screened in 14 BCs, 5 normal bladder epithelium (NBE) samples and 3 BC cell lines. We identified a subset of 7 miRNAs (miR-145, miR-30a-3p, miR-133a, miR-133b, miR-195, miR-125b and miR-199a*) that were significantly downregulated in BCs. To confirm these results, 104 BCs and 31 NBEs were subjected to real-time RT-PCR-based experiments, and the expression levels of each miRNA were significantly downregulated in BCs (p < 0.0001 in all). Receiver-operating characteristic curve analysis revealed that the expression levels of these miRNAs had good sensitivity (>70%) and specificity (>75%) to distinguish BC from NBE. Our target search algorithm and gene-expression profiling in BCs (Kawakami et al., Oncol Rep 2006;16:521-31) revealed that Keratin7 (KRT7) mRNA was a common target of the downregulated miRNAs, and the mRNA expression levels of KRT7 were significantly higher in BCs than in NBEs (p 5 0.0004). Spearman rank correlation analysis revealed significant inverse correlations between KRT7 mRNA expression and each downregulated miRNA (p < 0.0001 in all). Gain-of-function analysis revealed that KRT7 mRNA was significantly reduced by transfection of 3 miRNAs (miR-30-3p, miR-133a and miR-199a*) in the BC cell line (KK47). In addition, significant decreases in cell growth were observed after transfection of 3 miRNAs and si-KRT7 in KK47, suggesting that miR-30-3p, miR-133a and miR-199a* may have a tumor suppressive function through the mechanism underlying transcriptional repression of KRT7. ' 2009 UICC

A disintegrin and metalloproteases (ADAM) are cell membraneanchored proteins with potential implications for the metastasis of human cancer cells via cell adhesion and protease activities. In prostate cancer (PC), the ADAM-10 protein showed a nuclear localization whereas in benign prostate hypertrophy (BPH) it was predominantly bound to the cell membrane. We hypothesized that the pathogenesis and progression of PC are attributable to the nuclear translocation of ADAM-10. Immunoblotting revealed that after 5α α α α-dihydrotestosterone treatment, a 60-kDa active form of ADAM-10 was increased in the nuclear fraction but decreased in the cell membrane and cytoplasmic fractions of human androgendependent PC cells. Immunocytochemistry revealed that after 5α α α α-dihydrotestosterone treatment, the ADAM-10 protein was translocated from the cell membrane to the nucleus. Coimmunoprecipitation of androgen receptor and ADAM-10 was detected in the nuclear fraction but not in the cell membrane and cytoplasmic fractions. Immunohistochemical study of 64 PC and 20 BPH samples showed that the intensity of ADAM-10 staining was significantly higher in the nuclei of PC cells than in the nuclei of BPH cells (P < 0.0001). It was also significantly lower in the cell membrane of PC cells than in the cell membrane of BPH cells (P = 0.0017). Nuclear staining intensity was significantly correlated with the clinical Tfactor (P = 0.004), the Gleason score (P < 0.0001) and preoperative prostate-specific antigen levels (P = 0.0061). ADAM-10 small interfering RNA transfectants showed a significant decrease in cell growth compared to the controls. Our results suggest that in human PC, the nuclear translocation of ADAM-10 coupled with the androgen receptor is involved in tumor growth and progression. (Cancer Sci 2007; 98: 1720-1726) A disintegrin and metalloproteases (ADAM) are members of the metzincin (zinc-dependent metalloprotease) superfamily. They are cell membrane-anchored cell surface proteins involved in the proteolytic processing of other transmembrane proteins, in cell adhesion and in cell signaling events.(1-3) Among the more than 30 characterized ADAM proteins, ADAM-9, -10 and -17 act as cell surface 'sheddases', cleaving the extracellular (ecto) domains of cell membrane-bound proteins, including amyloid precursor proteins that have been investigated in Alzheimer's disease.(4) These ADAM are highly expressed in human breast, lung, stomach, colon, pancreas, uterine, ovarian and prostate cancer.(5-11) They activate growth factors such as epidermal growth factor and transforming growth factor-α, cytokines such as tumor necrosis factor-α, and degrade cell adhesion molecules such as CD44, L1 and collagens, all of which are synthesized as precursors and are responsible for cancer development. (12,13) Prostate cancer (PC) is one of the most common malignancies among men. Global cancer statistics indicated that in 2002, 5.8% of cancer deaths in men and 3.3% of all cancer deaths were attributable to PC. (14) In the development of PC, 5α-dihyd...

Background:The aim of this study is to find a novel molecular target based on chromosomal alteration and array-based gene expression analyses in bladder cancer (BC). We investigated a cancer testis antigen, LY6K, which is located on chromosome 8q24.3.Methods:Five BC cell lines were subjected to high-resolution array-comparative genomic hybridisation with 244 000 probes. The expression levels of LY6K mRNA were evaluated in BC cell lines and clinical BC specimens by real-time reverse transcription–PCR. The cell lines were subjected to fluorescence in situ hybridisation of LY6K. Cell viability was evaluated by cell growth, wound healing, and matrigel invasion assays.Results:Typical gained loci (P<0.0001) at 6p21.33-p21.32, 8q24.3, 9q34.13, 11q13.1-q14.1, 12q13.12-q13.13, 16p13.3, and 20q11.21-q13.33 were observed in all of the cell lines. We focused on 8q24.3 locus where LY6K gene harbours, and it was the top upregulated one in the gene profile from the BC cell line. LY6K mRNA expression was significantly higher in 91 BCs than in 37 normal bladder epitheliums (P<0.0001). Fluorescence in situ hybridisation validated that the high LY6K mRNA expression was due to gene amplification in the region where the gene harbours. Cell viability assays demonstrated that significant inhibitions of cell growth, migration, and invasion occured in LY6K knock down BC cell lines; converse phenomena were observed in a stable LY6K transfectant; and LY6K knockdown of the transfectant retrieved the original phenotype from the LY6K transfectant.Conclusion:Upregulation of the oncogenic LY6K gene located on the gained locus at 8q24.3 may contribute BC development.

To our knowledge we report the first study demonstrating that the mechanism of UCHL1 down-regulation in renal cell carcinoma is through CpG hypermethylation of the promoter region and methylation of the UCHL1 gene is associated with a poor prognosis in patients with renal cell carcinoma.